This invention relates to an improved sound wall of the type used along roads and freeways to block traffic noise from adjacent landowners as well as block the view of the road or freeway.
Sound walls have become a popular way to reduce noise pollution from freeways and highways into adjacent residential and commercial neighborhoods located on the other side of the walls. These walls have been constructed with the desired goal of reducing noise from passing traffic into neighborhoods. Additionally, such walls not only provide noise reduction, but added security features. Because the dimensions of the walls are generally fairly high and quite long, people and objects from the freeway or highway do not enter the residential neighborhoods. Therefore, there is no disturbance to either the residents or alternatively to their houses or property. Additionally, they also serve as a safety device to stop pedestrian traffic across major roads or freeways.
Known sound walls are typically thin (about 6xe2x80x3 thick) and often have an attractive pattern or profile molded into the traffic side or sometimes both sides. Many prior art walls have been built up of bricks, concrete blocks, or other types of masonry. Recent environmental concerns have even led to the creation of sound walls which include various types of living plants so that both the sound is absorbed and, additionally, the walls trap many airborne particles and create a natural carbon monoxide uptake. Construction of these walls has generally been labor intensive and expensive and additionally such walls become unstable with increasing height.
Sound walls are normally subject to elements such as wind loads and earthquake shaking depending on where they are located. For example, in eastern Colorado, the wind loads can be quite severe in the open country. Alternatively, in seismically active areas such as California, these walls can be subject to severe earthquake activity.
Past practice in constructing sound walls has typically been to cast concrete walls within a two-sided form. Vertical molds with an approximately 6xe2x80x3 interior width are formed. These forms contain liners on their inner or facing sides. A re-bar lattice or steel mesh is placed inside the mold and then concrete is pumped or poured into the mold. This practice often leads to problems in forming the sound wall panels because the concrete does not flow well through the narrow forms, and this often results in non-uniformity of the finished texture or pattern. This practice leads to products that are not uniform throughout and therefore weaker in certain spots than others. This is particularly true towards the bottom of the mold, resulting in honeycombed areas.
In order to overcome the above problems, previous sound walls have often been poured only to a shallow depth, using short forms. These forms have been on the order of only 2xe2x80x2 to 3xe2x80x2 tall and are then constructed in layers to achieve greater height. This solution leaves the concrete more uniform in nature, but presents another problem in that it results in a finished wall with a series of unattractive horizontal joint lines every 2xe2x80x2 to 3xe2x80x2 up the entire length of the wall.
Therefore, there is a need for a sound wall system that provides noise reduction, is easy to form and install, and maintains consistent structure and aesthetics throughout.
It is an object of the present invention to provide a new and improved sound wall construction and method for making the same.
According to one aspect of the present invention, a dual membered sound wall panel is provided. First and second corresponding half-panels are formed. These half-panels have inner surfaces and outer surfaces that may be textured in order to be aesthetically appealing. The textured outer surfaces may be of the same pattern or alternatively they may be different from one another. If no textured pattern is desired there does not have to be any texture on the surface. The outer textured surface can be made of one of many different forms depending on the look desired. The half-forms also have opposing first and second ends and additionally opposite sides. Contained on the inner surfaces of the half-planes are connectors. These connectors are embedded into and around the periphery of the half-panels. The first and second half-panels are oriented with their inner faces oriented towards each other on parallel planes. This configuration positions the connectors of both half-plates facing each other. The outer surfaces of both the half-plates are positioned away from each other so that they are exposed externally while the faces with the connectors are contained internally and are not exposed. Several spacer plates are contained between the first and second half-plates. These spacers allow a gap to be defined between the two half-panels. The connectors of the half-plates may be made of steel angle irons and therefore allow for connection of the two half-plates to be made by welding the angle irons of each half-plate to each other. Alternatively, one skilled in the field will realize that the two half-plates may be connected to each other by any other suitable means. Such means include but are not limited to bolted connections, pin-and slot connectors, or any welded connectors. Additionally, if it is so desired, the gap created between the two half-plates may be filled with sound absorbing material in order to further reduce any noise pollution.
Once the dual membered panels are completed, a plurality of panels are positioned in an orientation that completes a wall structure. The dimensions of such a constructed wall are limited only in the ability of the panels to be self supporting when they are oriented into position. The placement of such completed sound walls would be like any other sound walls currently available and be used for purposes such as structural support, maintaining backfill, or merely diminishing sound pollution.
An advantage of the present invention is that because the two half-panel sections can be oriented with the gap between them, should one plate require removal, this may be done without disturbing the other plate. If only one side of the sound wall is damaged, that portion may be removed by burning off the connectors from one side and removing them while the other side remains in place. This provides a great advantage in that the damaged half-panel can be replaced and re-connected into position without losing the value or function of the sound wall in the interim. Also, because only part of the section of the wall needs to be replaced, this cuts down on costs associated with maintaining the sound wall. Even considering the fact that the present sound wall construction requires a modestly greater thickness (typically 7xc2xdxe2x80x3 as opposed to 6xe2x80x3), the present embodiment is still competitive in terms of price relative to the prior sound walls. The added thickness does not significantly alter the total cost of completion and installation because the casting is easier and less expensive than trying to pour a thin wall between forms as in the previous sound wall constructions.
Another advantage is that in certain highway applications where sound wall panels are required to have a formliner or architectural finish on one or both sides, the present invention removes the previous problem associated with sound walls. The present invention does not result in a poor quality finish or unacceptable differences in the quality of the finish that can occur on the opposite faces of a single panel.
Additionally, because the construction of the sound wall system is more efficient than in the past, there is an increase in the number of applications. For example, the system may be used as sound absorbent fencing for residential properties. Within neighborhoods often there is a need for noise reduction for things other than traffic or freeway noise. The sound wall system may provide both privacy and efficient noise reduction for people who desire such for their houses. Also, commercial buildings around industrial or power plants may find value in utilizing the sound wall construction because it is an economical way to allow operations to continue with minimal interference to surrounding elements. Not only does the sound wall system reduce noise, but the aesthetic appearance of the system can disguise the industrial setting to any surrounding area.
According to another embodiment of the present invention, a method of making a dual membered sound wall construction from two pre-formed half-panels is provided, which comprises the steps of placing a mold box horizontally on a work table that is the same size as the desired face of the half-panels. The mold box has a closed base, upstanding side and end walls, and an open top part. If it is desired that the outer surface of the half-panel be textured, a textured form liner is placed into the mold box. Then a layer of re-bar is installed into the mold box that extends across the entire length and width of the mold box. If a textured liner is placed into the mold box, then the re-bar mesh is spaced between the top of the liner, and the top of the box. However, if no liner is desired, the re-bar mesh is spaced between the top and bottom of the box. Alternatively, the textured surface may be created by use of a stamp apparatus that presses a profile into the back side of the panel on the table. Then numerous embedment angle irons are placed at spaced intervals around the periphery of the open top of the box. Each of the angle irons has a first leg extending downwardly adjacent a respective wall of the box and a second leg projecting inwardly and coplanar with the open top of the box. After that, enough concrete is poured to fill the mold box. Once the concrete has been poured, the concrete panel is allowed to set so that the re-bar is embedded within and the angle irons are positioned around the periphery of the inner face of the half-panel. The concrete panel may be allowed to set while in the horizontal position, or alternatively, the table on which the mold box is positioned may tilt up and allow the mold to be removed while still in the semi-set form. The panel may then be allowed to set at another location. The above described steps are then repeated in order to form a corresponding second half-panel. The two formed half-panels are then positioned face to face so that the inner faces of each half-panel are facing inwards. This orientation means that the outer surfaces are exposed while the inner surfaces are not exposed but are contained entirely within the internal structure of the dual membered panel. The two half-panels are then secured either by welding together the facing fillet angle irons or alternatively bolting, tying, or bonding the angle irons in any other appropriate manner.
The construction of the sound wall with the use of two separate pre-formed members allows each section of the sound wall to be constructed solidly and in a more uniform manner than previously available. The construction of the present sound wall does not suffer from honeycombing and does not result in poor facing profile reproduction. Finally, the present invention does not cause horizontal or vertical lines in the final construction as did the prior art walls.